Sony RB1G Service Manual page 330

Troubleshooting
3-3-4. Main Board Power On Checking (for Main SP Lch & Rch)
No Checking Item
1 Check
IC4601 side-terminal of
L4601,L4602,
L4603,L4604
2 Check F4601 MainSP
(for BA2 and BM board only)
3 Check F4601 MainSP
(for BKE, BKX , BKJ BLE,
BLX and BLJ board only)
4 Check IC4601 (Pin 8) and
C4601 (Pin 27)
(for BKE, BKX , BKJ BLE,
BLX and BLJ board only)
OK
Switching Freq = 384kHz or 768KHz
±20KHz
Vrms = dont care
V(before fuse) = 12.5V ± 0.5V
V(after fuse) = 12.5V ± 0.5 V
V(before fuse) = 19.5V ± 0.5V
V(after fuse) = 19.5V ± 0.5 V
V(before fuse) = 3.3V ± 0.5V
V(after fuse) = 3.3V ± 0.5 V
If  NG
NG
No switching Go to next checking.
frequency at either
one of the CL
No voltage. Check fuse broken?
Check CN9101 Pin 8 &10
got 12.5V?
No voltage.
No voltage.
RB1G CHASSIS
W600A/ W603A/ W605A/ W607A/ W650A/ W651A/ W653A/
W654A/ W655A/ W656A/W657A/ W658A/ W670A/ W674A
If  NG
Change fuse (5A).
Check power supply board
audio VCC.
Change fuse (5A).
Check power supply board
audio VCC.
Check +3.3V_MAIN
supply.
Size B* Board Type
(Segment: LW)
OTHERS EUROPE JP
24" BLX BLE BLJ
32" BKX/BLX BKE/BLE BKJ/BLJ
42" BKX/BLX BKE/BLE BKJ/BLJ
50" BLX BLE -
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